1. Field of the Invention
The present invention relates to a continuous screw tightening machine which, in order to fix a plate material, such as a wooden plate, a metallic plate or a gypsum plate, on the floor or the like, continuously tightens screws without the need for using a conventional screw gang element containing a number of screws arranged at prescribed intervals in a row by means of a belt-like member.
2. Description of the Related Art
Conventionally, in order to screw-fix a plate material, such as a wooden plate, a metallic plate or a gypsum plate, on the floor or other object, a continuous screw tightening machine which can continuously tighten screws has been proposed.
This type of continuous screw tightening machine is exemplified by a continuous screw tightening machine with which a screw gang element containing a number of screws arranged at prescribed intervals in a row by means of a belt-like member is loaded in the screw tightening machine main body for tightening a screw while feeding another screw, but before the advent of the continuous screw tightening machine, the single-shot screw tightening machine with which a single-part screw is charged into the screw tightening machine main body one at a time and screwed-in into the object one by one had been used.
The patent document 1 discloses a continuous screw tightening machine with which the screw gang element is loaded in the screw tightening machine main body for tightening a screw while feeding another screw. With this machine, a driving machine is incorporated in the tightening machine main body on which a grip handle is formed; to the front of the tightening machine main body is mounted a screw feed mechanism main body through a pair of guide poles such that the screw feed mechanism main body is capable of being slid in the longitudinal direction; between the pair of guide poles is parallel disposed a bit for tightening the screw, and this bit is removably connected to a clutch such that it is rotation-driven through a rotating spindle, a reduction gear, and the clutch; and to the screw feed mechanism main body is mounted a magazine accommodating a screw gang element containing screws arranged in a row by means of a belt-like member and then rolled. Although the patent document discloses a continuous screw tightening machine with which a magazine accommodating said screw gang element is mounted, a continuous screw tightening machine with which the magazine is not used, but only said screw gang element is used is also available.
However, with the continuous screw tightening machine as disclosed in the patent document 1, the screw gang element is employed, and to use this continuous screw tightening machine, the screw gang element containing a number of screws arranged by means of a belt-like member must be previously formed; the formation of the screw gang element itself is complicated and thus the expense for it is high; and due to the amount of such expense, the operating cost of the continuous screw tightening machine has been high. The continuous screw tightening machine as disclosed in the patent document 1 is a machine of the type which must use the screw gang element, regardless of whether the magazine is used or not.
The patent document 2 discloses a portable fastening bit power driving tool which is of one-by-one tightening type. With this tool, one portion of a main body formed in the shape of a Y comprises an upper tube, a driving spindle, and a driving tool. The other portion comprises a supply tube which supplies a single-part screw. The upper tube and the supply tube are connected to the lower tube. Also, the upper tube and the driving spindle are configured such that they are capable of being reciprocated with respect to the lower tube. An escape apparatus, which is synchronized with the motion of the upper tube and the driving spindle, is provided, and by the motion of the upper tube, the escape apparatus is operated to supply a fastening bit to the lower tube during the return stroke of the driving tool.
However, the portable fastening bit power driving tool as disclosed in the patent document 2 is constructed such that the screw is charged one by one into the supply tube, thus it is, of course, impossible to carry out a continuous screw tightening operation. When a plurality of screws are accidentally charged into the supply tube, blocking is caused; and if a screw is charged in a reverse orientation, there will arise the need for taking it out. Other disadvantages are involved, and thus, every time one cycle of a tightening operation is completed, the subsequent screw must be confirmed for its orientation before being charged into the supply tube. Thus, an extremely time-consuming operation is required, and the operation efficiency is extremely low.
Patent Document 1
Patent Publication No. JP/P09-136269A/1997
Patent Document 2
Patent Publication No. JP/P52-1699A/1977